Friday, January 20, 2012

(Reuters) - Researchers studying a potentially more lethal, airborne version of the bird flu virus have suspended their studies because of concerns the mutant virus they have created could be used as a devastating form of bioterrorism or accidentally escape the lab.

In a letter published in the journals Nature and Science on Friday, 39 scientists defended the research as crucial to public health efforts, including surveillance programs to detect when the H5N1 influenza virus might mutate and spark a pandemic.

But they are bowing to fear that has become widespread since media reports discussed the studies in December that the engineered viruses "may escape from the laboratories" -- not unlike the frightful scenario in the 1971 science fiction movie "The Andromeda Strain" -- or possibly be used to create a bioterror weapon.

Among the scientists who signed the letter were leaders of the two teams that have spearheaded the research, at Erasmus Medical College in the Netherlands and the University of Wisconsin, Madison, as well as influenza experts at institutions ranging from the U.S. Centers for Disease Control and Prevention to the University of Hong Kong.

The decision to suspend the research for 60 days "was totally voluntarily," virologist Ron Fouchier of Erasmus told Reuters. The pause is meant to allow global health agencies and governments to weigh the benefits of the research and agree on ways to minimize its risk.

"It is the right thing to do, given the controversies in the U.S.," Fouchier said.

The U.S. National Science Advisory Board for Biosecurity in December had asked Science and Nature to censor details of the research from the Erasmus and Wisconsin teams that was submitted for publication.

Biosecurity experts fear that a form of the virus that is transmissible through airborne droplets--which the Erasmus and Wisconsin teams independently created--could spark a pandemic worse than the 1918-19 outbreak of Spanish flu that killed up to 40 million people.

"There is obviously a controversy here over the right balance between risk and benefit," says virologist Daniel Perez of the University of Maryland, who signed the letter supporting the moratorium. "I strongly believe that this research needs to continue, but that doesn't mean you can't call a time out."

The researchers' decision shifts the focus of debate from whether the studies should be made public to whether they should have been done at all, given the theoretical possibility that a highly infectious virus could be stolen or escape from a lab. Some of the studies were funded by the U.S. National Institutes of Health.

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases at NIH, told Reuters that the decision to fund the research was justified.

"The proposal the investigators put forth to do this research was appropriate," said Fauci, who was "actively involved" in the decision to call a moratorium on the research. "The value of the research is clear, as even the biosecurity board unanimously agreed."

CONTAGIOUS AMONG HUMANS

In its current form, people can contract H5N1 only through close contact with ducks, chickens, or other birds that carry it, and not from infected individuals.

But when H5N1 acquires mutations that allow it to live in the upper respiratory tract rather than the lower, it can travel via airborne droplets between infected ferrets, which are considered good models of how flu viruses behave in people.

The teams at Wisconsin, led by Yoshihiro Kawaoka, and Erasmus induced as few as three mutations that allow the virus to be transmitted through the air between ferrets. It is not known whether the mutant H5N1 can be spread between people in a similar way, by coughing or sneezing, since such experiments would be unethical.

But the fear is that the mutations that allow H5N1 to spread via the air between ferrets would allow it to do in people, making it exponentially more contagious.

To give the scientific community and governments time to determine whether the research can be conducted safely, the scientists write, "We have agreed on a voluntary pause of 60 days on any research involving highly pathogenic avian influenza H5N1 viruses" that produce easily contagious forms of the virus.

In particular, they wrote, no experiments with live, mutant viruses "already shown to be transmissible in ferrets will be conducted during this time."

Fouchier noted in an essay published Thursday in Nature that other laboratories around the world may also be close to an airborne bird flu virus, and may not even be aware of it.

HOW SAFE ARE THOSE LABS?

Critics have more recently raised concerns over the safety of the physical environment in which the experiments were being conducted, in addition to the question over whether details of the research should be made public. For now, Science and Nature are withholding publication of the studies.

Nature reported last month that both experiments on mutant viruses were carried out in labs rated "biosafety level 3 (BSL-3) enhanced," which "require scientists to shower and change clothes when leaving the lab, and include other safety features such as negative air pressure and passing exhaust air through high-efficiency particulate air filters."

That is widely believed to protect against an accidental release of the virus. But some virologists argue that the more stringent BSL-4 precautions are needed. BSL-4, which is required for research on, among other microbes, the Ebola virus, includes full-body positive air-pressure suits like astronauts use. In the past, the SARS (severe acute respiratory syndrome) virus has escaped from BSL-3, and possibly BSL-4, labs.

"It's a responsible decision to suspend work on these viruses while agreement is being reached," said Peter Openshaw, Director of the Centre for Respiratory Infection at Imperial College London. "I hope that these issues can be resolved and that this vital work will continue under appropriate conditions and not be driven underground."

Scientists and government officials are expected to meet in Geneva in February at the World Health Organization, to decide how research on mutant H5N1 should proceed.

Sunday, December 18, 2011

You could be turning deaf because of your headphones. Our expert lists a guide of what you should avoid while listening to your favourite tracks on the go

Is music your safe haven from the hellish traffic jams you travel through everyday? You might need to re-think this strategy. Drowning out incessant honking on our potholeridden roads with Comfortably Numb, might just be numbing your eardrums for life. Like Rajeev Khandelwal who loses his hearing in Soundtrack, thanks to his constant use of headphones as a DJ; the actor's on-screen nightmare can actually become your reality.

In today's world of iPods and phones that can play music, most people are plugged in constantly. Our expert Dr Nishit Shah, ENT consultant at Bombay Hospital tells you what you can do to avoid losing your sense of sound.

Play it loud

Listening to music at half the volume your player is obviously not damaging. It all depends on the volume and how long you are listening to it. Shah says, "There are guidelines laid down by World Health Organization as to what decibels are permissible. Most workplaces and music player manufacturers adhere to these guidelines. But constant exposure is still a problem." Cranking up the volume for longer periods of time is very dangerous, and can lead to partial deafness. The higher the volume gets the lesser amount of time the ear can take it.

Uncomfortably numb

Unlike people who go deaf during a bomb blast or hearing the sonic boom of a plane, deafness caused by headphones creeps on you and if not checked, the effects can be adverse. "I have seen people who show no obvious signs of deafness when they are young, can hardly hear anything when they reach their 60s." Studies show that this is common among people who go for a lot of concerts and clubs. Shah says, "Deafness caused due to listening to music does not happen overnight. The ear warns you before things can get really bad with tinnitus.

You get a ringing sound in your ear, which means hearing loss is imminent. When you exit a club, your ears feel relieved and you can't hear too well immediately. That's because your ears are adapting to the new environment."

In fact, Shah says that moving from an extremely loud place (like a club) to an extremely quiet place can be more damaging than exposing yourself to higher decibels for longer.

Right hear, right now

Studies have shown that other than musicians and people in studios who want to listen to intricate sounds of a particular track, most people listen to music on headphones loudly to drown out background noise. The standard ear piece or even normal headphones are no good. Shah recommends using in-ear headsets or noise reduction/cancellation headphones that naturally drown out background noise. He says, "People who use these headsets have a tendency to listen to music at a lower volume anyway. So, if you want to listen to something throughout the day this would be the best way to avoid loss of hearing."

The cure

The scariest part about losing your hearing ability is that there is nothing you can do to regain it. The strongest preventive drug doctors prescribe is "common sense". Shah says, "Most people don't buy headphones because of quality, they buy it because it is loud enough. How do you tell people otherwise? You have to be aware of what is happening to your ears. As soon as you feel any discomfort, take a break. You cannot listen to music loudly for eight hours in a row. This will obviously affect your hearing."

If you feel like you are losing your sense of hearing, head to an ENT immediately. In the first few days of being affected, your hearing can be repaired with the help of steroids, but very few people actually spot the impediment so soon. Then, of course, there are hearing aids. These are used when the damage is already done though, and you want to avoid that altogether.

Just how much is too much?

Research suggests that risk of permanent hearing loss goes up with just five minutes of exposure a day to music at full volume. Traffic noise is at about 70 to 80 decibels. If you're trying to drown this out, you will hit dangerous decibel levels. Listening to earbuds, or in-ear headphones, for 90 minutes a day at 80 percent volume is probably safe. However, different brands have different volumes and that needs to be factored into the decision to buy headsets.